Why should that be?
Because the SSPX churches only ever host the Latin Mass; the sanctuary is untainted by odd bods who stroll across at various times during the day, no Eucharistic ministers (ever) no female servers, no 'Shine, Jesus, shine' only sacred chant that catapults us back to the plaintive chants of the Jewish priests in the temple.
No one gives a bow when crossing in front of the tabernacle, communion rails are in place - all is right and proper.
The altar servers are young and competent, the priest reverent and practising full custody of the eyes.
This video clip is from the SSPX church in Paris, St Nicolas du Chardonnet.
A beautiful church and a fitting house for Almighty God - allow yourself an hour or so to pray and enjoy this most moving Mass..........